1. Field of the Invention
The invention is directed to a bush bearing, preferably a rubber-metal-bearing, in the form of a bushing having zones with different or changing radial stiffness arranged in the circumferential direction. The different radial stiffness or force-displacement characteristic can be achieved by providing the bearing in a first major radial load-bearing direction with at least one radial web having a high stiffness, which is formed by consecutive layers of alternating elastomer and metal elements and/or plastic elements. At least one pocket is formed in a second radial direction which is preferably oriented perpendicular to the first radial direction, wherein the pocket reduces the radial stiffness of the bearing in this region.
Bush bearings have to satisfy quite different requirements because they are used in many different applications. The different design of the bearings is evident in particular in automotive applications. Bush bearings with different radial stiffnesses or force-displacement characteristics along their circumference are required, inter alia, for supporting chassis components. The bearings in these applications have different radial stiffnesses with a large force-displacement ratio, i.e., they have regions with a high radial stiffness and other regions with a comparatively much smaller radial stiffness. These conventional types of bearings can be implemented by adapting the bearing geometry, so that a radial web with a high stiffness is formed in at least one radial direction and, preferably perpendicular thereto, at least one pocket is formed with an elastomer bearing body having a smaller stiffness in that region.
2. Description of Related Art
A bearing constructed in this manner is known, for example, from DE 35 36 284 A1. This bearing attains its high stiffness in the region of the radial web by constructing the radial web of an alternating layered sequence of elastomer and intermediate elements of sheet metal, which also produces a relatively large force-displacement ratio in the region of the web and the pocket arranged perpendicular thereto. In the bearing described in the document, the bearing body is vulcanized on and adheres to a metal inner element. As a result, the bearing described in the document has a stiff torsion which is undesirable and unsuitable for many applications. Other applications are known which call for a still higher force-displacement ratio between the circumferential regions representing the radial web and the pocket.
It is known to lower the torsion of bush bearings by providing an additional inner low-torsion bearing or an intermediate tube. This design, however, further complicates the bearing geometry and also increases the manufacturing cost.
It is therefore an object of the invention to form a bush bearing of simpler design with at least one radial web and a pocket, while still providing a large force-displacement ratio and simultaneously a soft torsion characteristic.